Fraunhofer Institute for Applied Information Technology FITPetroScan II: System for virtual polarization microscopy
Unique Selling Point
The unique and innovative character of the PetroScan system results from the interaction of hardware and software based on the Kansy interpolation developed at Fraunhofer FIT. The Kansy interpolation calculates the representation of pixels between defined polarization angles, which serve as supporting points. Only these points have to be recorded on the sample, accordingly the scan is accelerated and at the same time the amount of data generated is significantly reduced. Based on the generated data, samples can be viewed in a virtual microscopy environment with freely adjustable image magnification and polarization angle. The combination of Kansy interpolation with the virtual microscopy environment makes it possible to make digitized thin section samples accessible to experts without loss of information and regardless of location.
PetroScan Polarization Microscope
The optical design of the PetroScan microscope is based on the principle of classical polarization microscopy, using high-quality optical and mechanical components from well-known manufacturers. Using a motorized polarizer analyzer module, images can be captured in brightfield with cross-, circular- and unpolarized light in automated operation with commercially available objectives from 5x to 63x magnification. The images are acquired by a low-noise, peltier-cooled True Color CCD camera. A motorized XYZ precision stage enables the scanning of thin sections with dimensions of up to 130 x 85 mm. Due to the large Z-travel range of up to 50 mm, the examination of strongly voluminous samples in polarized incident light is also possible.
PetroScan Analysis Software
The PetroScan analysis software makes it possible to view each sample in its entirety or in a magnified display at any adjustable polarization angle in the Tile Viewer after the thin sections have been digitized. The data sets can also be transmitted, so that the digitized thin section samples can be viewed and analyzed at any location, provided a suitable system with installed Tile Viewer is available.
Innovations with PetroScan II
An essential factor for the time required to scan a thin section is the total number of tiles needed to display the overall picture of the sample. Therefore, the illumination for the second version of the PetroScan system was fundamentally revised and now allows larger parts of the sample to be imaged on the CCD chip per tile recorded. In addition, the revised illumination allows homogeneous illumination of the field of view of objectives up to 5x magnification (previously 10x), whereby this is imaged full-frame on the 1‘‘ chip of the newly integrated 6 megapixel true color CCD camera. The combination of revised illumination, new camera and lower resolution lenses allows an enormous acceleration of the scan process compared to the PetroScan I system (min. 10x).